Anthropic: Claude Fable 5 vs Anthropic Claude Sonnet 5.5: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Anthropic: Claude Fable 5 (anthropic/claude-fable-5) vs Anthropic Claude Sonnet 5.5 (claude-sonnet-5-5). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Anthropic: Claude Fable 5 (anthropic/claude-fable-5) — $25,000 Startup Credits & 50% Cache Promo
Anthropic's Q4 2026 developer promotion combines $25,000 in Claude API credits for early-stage builders with a permanent 20% base price reduction on Opus 5.5 ($4/$20), 0.05x ($0.20/1M) prompt cache reads, and 50% off Batch API processing ($2/$10 with 300K max output).
Sonnet 5.5 High-Velocity Coding Promo: $0.10/1M Cached Input & $1/$5 Batch Tier
Anthropic's September/October 2026 rollout prices Claude Sonnet 5.5 at half of Opus 5.5 ($2/$10) while activating $0.10/1M (0.05x) cached input reads and $1.00/$5.00 asynchronous batch processing.
In Etuki October 2026 FinOps telemetry comparing Anthropic: Claude Fable 5 (API ID: anthropic/claude-fable-5) vs Anthropic Claude Sonnet 5.5 (API ID: claude-sonnet-5-5), Anthropic Claude Sonnet 5.5 offers lower standard input pricing at $2/1M tokens ($10/1M output), while Anthropic Claude Sonnet 5.5 leads in cached prefix economics at $0.1/1M tokens (95% discount). Anthropic Claude Sonnet 5.5 achieves a 50ms faster P90 time-to-first-token latency (230ms vs 280ms).
Auto-discovered via live global telemetry registry.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | Anthropic: Claude Fable 5 | Anthropic Claude Sonnet 5.5 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | anthropic/claude-fable-5 | claude-sonnet-5-5 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $10 / $50 | $2 / $10 | Anthropic Claude Sonnet 5.5 |
| Cache Read Price (per 1M) | $5/1M (50% Off) | $0.1/1M (95% Off) | Anthropic Claude Sonnet 5.5 |
| Context Window / Max Output | 977K In / 125K Out | 1000K In / 128K Out | Anthropic Claude Sonnet 5.5 |
| P90 First-Token / Edge Latency | 280ms | 230ms | Anthropic Claude Sonnet 5.5 (-50ms) |
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning sup
Released Sept 28, 2026 at half of Opus 5.5 price with 0.05x ($0.10/1M) cache reads for high-speed SWE agents.
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🎼Switch from Anthropic: Claude Fable 5 to Anthropic Claude Sonnet 5.5
Released Sept 28, 2026 at half of Opus 5.5 price with 0.05x ($0.10/1M) cache reads for high-speed SWE agents. Verified P90 latency of 230ms.